It's called logic. Jiu Jitsu isn't like, for instance, karate, where you can be at blue belt within a year. If you were at blue belt, you'd been going to a gym that presumably wasn't free for a few years. Few people have a job that pays well enough to pay for martial arts classes and lessons at 16 or 17, and those who do don't have the time and energy left after working and going to school to be in those classes. Therefore, someone else was almost certainly supporting you and paying for your lessons.

So the truths you think are universal and can be applied to anyone actually are unique to a certain set of circumstances you lucked into.